Cyclists should wear an effective air mask or better move away from the busy roads. That’s the conclusion I got when looking at the animated 3D ‘Pollution map’ video of London. The orange yellow color, mainly along the main roads, indicates high level of air pollution where the blue color are area with better air quality. It is intuitive to think air pollution level is higher along the main roads and lower away from the main roads, but I could never imagine the differences can be so huge!
In the short video below you can see the highest air pollution concentrated right along the main roads and junctions, likely the result of slow moving vehicles there. Most of the area away from the main roads are much better.
If you are waiting for the green light at any of such junctions, hold your breath. Because the ultra fine particles (0.1-0.3 micros, currently not being regulated) can travel deep down into the lungs and stay longer there than their bigger brothers (>2.5 microns). Ultra fine particles reduces the health benefits of physical exercise. There are increased evidence showing these ultra-fine particles are the silence killer closely links to respiratory and cardiovascular diseases.